Attractive polaron formed in doped nonchiral/chiral parabolic system within ladder approximation

Abstract

We investigate the properties of attractive polaron formed by a single impurity dressed with the particle-hole excitations in a three-dimensional (3D) doped (extrinsic) parabolic system. Base on the single particle-hole variational ansatz, we study the pair propagator, self-energy, and the non-self-consistent medium T -matrix. The non-self-consistent T -matrix discussed in this paper contains only the open channel since we don't consider the shift of center-of-mass due to the resonance (e.g., induced by the magnetic field). Besides, since we focus on the low-density regime of the majority particles, the effective Fermi wave vector is small. The scattering form factor is discussed in detail for the chiral case and compared to the non-chiral one. The effects of the bare coupling strength, which is momentum-cutoff-dependent, are also discussed. We found that the pair propagator and the related quantities, like the self-energy, spectral function, induced effective mass, and residue (spectral weight), all exhibit different features in the low-momentum regime and the high one, which also related to the polaronic instabilities as well as the many-body fluctuation and nonadiabatic/adiabatic dynamics. The pair-propagator and the energy relaxation time at finite temperature are also explored.

Electronic properties and polaronic dynamics of semi-Dirac system within Ladder approximation

“…At Ref. [87], we have proved that, at temperature T ≪ T F , where T F is the Fermi temperature, the polaron self-energy decreases with the increase of temperature, and the variation of selfenergy due to the temperture effect, which is an order of magnitude less than the one due to the variation of momentum of energy, also decreases with the increase of temperature, which is in agreement with Ref. [124].…”

“…Besides, the interparticle spacing closes to the mean-free path of the mobile impurity as required by the formation of polaron [41,42].…”

“…Similar to the procedure as we carried in Ref. [87], we consider the chiral effect into the pairing scattering event: an electron-hole pair (electron with momentum k and hole with momentum q) is excited in the fermi bath by the chiral semi-Dirac quasiparticle which with initial momentum p and final momentum p+q −k. The non-self-consistent T -matrix theory takes into account the higher-order pairing fluctuation than the Gaussian fluctuation [74], although the propagators of the two quasiparticle excitation are bare.…”

“…Note that unlike the calculation of DOS, we set a momentum cutoff the upper limit of integral over r k to prevent the problem of inconvergence, as we presented previously in Ref. [87]. Similar to the above transport scattering time, we here only consider the contribution from x-component of momentum of semi-Dirac quasiparticle but consider all components of momentum of the majority particle, i.e., the nonrelativistic parts.…”

Electronic properties of the Dirac and Weyl systems with first- and higher-order dispersion in non-Fermi-liquid picture

“…The many-body perturbation effect at the charge neutrality (the critical point) is related to the long-range Coulomb interaction and the coupling to the electronic critical mode [23]. Thus it is also interesting to considering the results in this paper to the polaron dynamics [78,77]. In the presence of the gapless order parameter fluctuation, the Landau damping of the longitudinal excitations within RPA for the non-Fermi-liquid case are also discussed.…”